Add unit test for this. Also updated documentation

Should truncate minimum negative values to lower edge. Use std functions to do this.

As a result of the bug fixed in PoldiFitPeaks1D, one unindexed peak that is not actually a peak is excluded, so the numbers need to be adjusted by one.

Updated algorithm category as well.

Doc output tag doesn't match input

Just the registration did not seem to be enough, as the parser class depends on pyparsing. Encapsulating everything into one try/catch block solves the issue.

These need to be present in the logs of the peak tables now, which they are when PoldiIndexKnownCompounds has been used to generate them. The docs contain a hint what to do when a custom indexing method has been used.

Previous naming scheme would overwrite indexed workspaces when using a compound multiple times.

Signed-off-by: Karl Palmen <karl.palmen@stfc.ac.uk>